Cervix dilating instrument and method

ABSTRACT

A DILATION INSTRUMENT AND PROCEDURE FOR DILATING THE CERVIX OF THE HUMAN UTERUS. THE INSTRUMENT IS OF GENERALLY CYLINDRICAL CROSS-SECTIONAL CONFIGURATION AND DIVERGES RADIALLY OUTWARDLY FROM ITS DISTAL END, WITH A MAXIMUM TAPER ADJACENT ITS END, AND A DIMINISHING TAPER ALONG ITS LENGTH. THE INSTRUMENT IS RELEASABLY CONNECTED TO A VIBRATING TOOL TO CAUSE LONGITUDINAL RECIPROCATING VIBRATORY MOTION TO BE IMPARTED. AN ADJUSTABLE STOP MEMBER IS PROVIDED TO CONTROL THE DEPTH OF PENETRATION OF THE INSTRUMENT INTO THE XERVIX AND UTERUS.

United States Patent [72] Inventor William C. Murr Piedmont, Calif. [21] App]. No. 758,256 [22] Filed Sept. 9, 1968 [45] Patented June 28, 1971 [73] Assignee Blo-Englneering,1nc.

[54] CERVIX DILATING INSTRUMENT AND METHOD 5 Claims, 4 Drawing Figs.

[52] 1.1.8. 128/341, 128/52 [51] Int. Cl. A61m 29/00 [50) Field ofSearcl: 128/341, 52, 343, 344, 348, 303, 242

[56] References Cited 7 UNITED STATES PATENTS 507,060 10/1893 Beavis 128/341 Primary Examiner-Dalton L. Truluck Attorney-Gardner and Zimmerman ABSTRACT: A dilation instrument and procedure for dilating the cervix of the human uterus. The instrument is of generally cylindrical cross-sectional configuration and diverges radially outwardly from its distal end, with a maximum taper adjacent its end, and a diminishing taper along its length. The instrument is releasably connected to a vibrating tool to cause longitudinal reciprocating vibratory motion to be imparted. An

adjustable stop member is provided to control the depth of penetration of the instrument into the cervix and uterus.

CERVIX DILATING INSTRUMENT AND METHOD BACKGROUND OF THE INVENTION One of the most frequently employed operative procedures in gynecology involves the dilation ofthe cervical canal which constitutes the narrow lower or outer end of the uterus. In some instances, cervical dilation is performed to permit easier egress of menstrual blood, but usually dilation and curettage are done concurrently. The cervical canal which is normally restricted in cross-sectional extent is dilated to permit the subsequent introduction of the curette, a tool permitting scraping of the uterine cavity. Presently employed methods for effecting cervical dilation possess a number of shortcomings For example, in one of the more conventionally employed procedures, the gynecologist will successively insert a plurality of increasingly larger instruments into the cervix. This process is not only time consuming, but requires considerable skill on the part of the physician to effect the required dilation, without tearing of the tissue and without excess penetration of the dilating tool into the uterus.

In accordance with the present invention, dilation may be quickly and effectively performed, without the dangers attendant to presently available techniques.

DRAWINGS FIG. I is a perspective view of the dilating tool of the present invention.

FIG. 2 is a longitudinal elevational view, partly in cross section of the tool.

FIG. 3 is a transverse cross-sectional view taken substantially in the plane indicated by line 3-3 of FIG. 2.

FIG. 4 is another longitudinal elevational view of the tool attached to a vibrator instrument and positioned in the cervical canal.

DESCRIPTION In broad terms, the apparatus and process of the present invention involves the use of a tapered tool adapted to be inserted in the cervical canal and vibrated along its longitudinal extent to facilitate cervix dilation. Means are also provided to limit entry of the tool so as to prevent accidental piercing of uterine wall with the end of the tool. As will be understood, the tool is formed of stainless steel or other material which permits the same to be sterilized by autoclaving or other sterilizing techniques.

With reference to the drawing, the apparatus of the invention comprises a dilating tool, generally designated by the numeral l0, and a drive means 12 for imparting longitudinal vibratory movement to the tool for a purpose to be hereinafter described. The tool includes a tip 14, a longitudinally extending tip holder or shank I6, and adjustable stop means 18 for limiting entry of the tip through the cervical canal and into the uterus.

The size and configuration of the tip I4 is of particular importance. The tip is of circular cross-sectional configuration throughout its length and the distal end 20 is smooth and rounded to permit ready inserting into the cervix 22 without damage to the cervical tissue. The size of the tip end 20 is preferably in the neighborhood of4 mm. in diameter which is small enough to permit cervical entry, but not large enough to prevent a piercing or perforation of the surrounding tissue. From the end 20, the tip is ofincreasing cross-sectional extent,

possessing a maximum diameter ofabout l l mm. adjacent the rear end 24 thereof. The latter dimension is sufficient to allow the passage of a curette or other surgical instrument after the tool 10 has been withdrawn, and the cervical opening dilated to the maximum tool size. Obviously, if a greater degree of dilation is required, a second step in dilation would be the insertion of another tool tip oflarger diameter.

It is significant to note that the degree of taper is not uniform throughout the tip length. As the tip passes through the cervical passage and the latter becomes dilated, the resistance of the surrounding tissue becomes greater. Ac-

cordingly, the tip is designed to provide added mechanical advantage to overcome tissue resistance by gradually decreasing the taper or slope. In other words, considering a tip length of about 5 cm., the diameter of the tip will increase from its minimum end diameter of4 mm. to possibly 9 mm. on the first half ofits length, with an increase of4 mm. to its maximum of l 1 mm. in the rear half of its length. The tip thus has a projectile configuration rather than a conical shape.

Tip 14 is rigidly supported on the front end of shank 16 in any suitable manner. As here shown, the rear end of the tip is provided with an axial threaded bore engageable with a threaded shank portion 26. Extending rearwardly from the threaded portion 26 is a second shank portion 28 having opposed flat surfaces 30 and 32, best shown in FIG. 3 of the drawing, and whose function will be hereinafter explained. Continuing rearwardly, the shank 16 has another threaded portion 34 and finally a terminal portion 36 having a peripheral groove 38 provided therein.

As illustrated in FIG. 4, the terminal shank portion 36 is adapted to be mounted in the chuck or work holder 40 of the drive means 12, any suitable detent 42 being utilized to snap into engagement with groove 38 to releasably hold the shank in operative position in the work holder. No particular description is made of the drive means since there are numerous tools available which convert rotary movement into reciprocatory movement. Insofar as the present invention is concerned, it is only necessary that the shank 16 be reciprocated at about 5,000 cycles per minute with a stroke of about I to 2 mm.

From the foregoing description the general manner of dilating the cervix should be apparent. The tip end is placed at the cervical opening and the drive means 12 actuated which produces a longitudinal vibratory movement on the shank and tip. The physician may thus gradually ease the tip into and through the cervical passage so that the entire length of the latter will be dilated to the maximum diameter of the tool tip at the rear end portion 24 thereof.

As an important feature of the invention, the means 18 are provided to limit the degree of penetration of the tip into the uterus to any desired extent and thereby prevent the top from engaging the uterus wall opposed to the cervical passage. Such means include a tubular sleeve 44 having a radically enlarged annular disc 46 at its front end and an internally threaded radially inwardly projecting flange 48 at its rear end, the latter being engaged with the threaded shank portion 34. In this manner, the stop disc 46 may be selectively positioned at different longitudinal distances along shank 16 from the tip 14. To retain the sleeve 44 in position, a nylon or similar washer 50 is wedged against the rear end surface of flange 48 by means of a nut 52 threadedly engaged on the shank threads 34. Both sleeve 44 and nut 52 preferably have knurled external surfaces to facilate their rotation and proper position along the length of the shank.

It will be recalled that the shank portion 28 which is disposed immediately rearwardly ofthe tip 14 has opposed flat wall surfaces. On surface 30 there is provided indicia 54 which designates the minimum and maximum size of the tip diameter, e.g. 4-1 I mm. The physician will thus readily determine the extent of dilation which will be accomplished. On the surface 32 there is provided two sets of indicia 56 and 58. lndicia 56 expresses the distance from the tip end 20 to the position of the stop disc 46. This will enable the physician to know that when the disc engages the cervix opening, the tip end will have protruded to same predetermined extent through the cervical passage and into the uterine cavity. The other indicia 58 indicates the spacing between the rear end portion of the tip and the stop disc so as to represent the extent of entry of the maximum diameter portion through the cervical passage. As will be appreciated, the large end 24 ofthe tip must pass completely through the passage to effect a proper dilation, and by preliminary examination, the physician will determine the length of the cervical passage and position, etc. of the uterine walls before setting the position of the stop disc 46.

As illustrated in FIG, 4, the disc 46 is set so that when the disc engages the cervix opening, the tip end 20 will extend 7 cm. from such opening, and the maximum tip portion 24 will be about 2% cm. from such opening.

The combination of the tip shape, the vibratory motion imparted to the tip, and the adjustable stop means combine to provide a surgical tool which is extremely simple to use, rapid in producing the desired dilation, and safe in preventing injury to the patient.

lclaim:

l. A cervix dilating instrument having a longitudinally extending tip adapted to enter the cervical passage, said tip having a rounded leading end and having a circular cross-sectional configuration, said tip being tapered and increasing in diameter from said leading end towards the rear end thereof with a maximum degree of taper occurring adjacent said leading end and a reduction in degree of taper occurring adjacent said rear end, a tip holder extending rearwardly from said rear end of said tip, and stop means carried by and adjustably positioned and securable along the length of said holder and adapted to limit the amount of entry of said tip through the cervical passage and into the uterus, said holder including a threaded shank portion, said stop means including an annular element having a diameter substantially in excess of the maximum diameter of said tip, and said element having means threadably engaged with said shank portion for selectively positioning said element in predetermined spaced relation to the rear end of said tip.

2. An instrument as set forth in claim 1 including means for vibrating said holder and said tip along the longitudinal axis thereof.

3. An instrument as set forth in claim 1 including indicia on said holder for indicating the distance of said stop means relative to said tip.

4. A method of dilating the cervical passage in a human female which consists of placing the front end ofa tip having a gradually increasing diameter against the cervical opening, connecting said tip to a mechanical vibrator, and vibrating said tip along its longitudinal axis while exerting forward pressure to cause the tip to enter and pass through the cervical passage.

5. A method as set forth in claim 4 in which said tip is caused to vibrate at about 5000 cycles per minute with a stroke of no more than about 2 mm. 

